Little Brother
by flamenightivy
Summary: Full summary is inside. I will just say that it involves Yukio and his little half brother Rin. Read and find out more. Will be a series of one-shots and arcs.
1. The Beginning Part 1

**Okay so I am fixing up this poor neglected story. I am now full fledged back into the Blue Exorcist fandom. THIS FIC IS NOT ABANDONED I AM JUST HORRIBLE AND NEGLECTFUL. ENJOY!**

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Prologue

Yukio stood outside the now quiet room, his mommy was taken in there when she started screaming. He hoped his mommy was okay, he had remembered hearing the word baby. Maybe he would be a brother? If so he would the happiest boy on the planet. He stood there anxiously waiting, the long he waited the more agonizing it became. It was when the screams stopped from his mother a new cry filled the room. It was a baby's cries.

Yukio's eyes widened. He was right! He was going to be a big brother! He tried to put his ear against the door only for it to be opened up by someone from the inside. He would have fell had it not been for the strong arms that picked him up and lifted him into their arms.

"Yukio?" The person asked, Yukio looked up to see his mommy's new husband. His name was Satan. He was very nice to Yukio, he didn't understand why people were scared of him. After his daddy being gone for years Yukio needed a male role model, it just happened to be Satan of all things to fill that role.

His step-daddy had medium length hair that his mommy loved to braid flowers into. Even though the demon king stood tall and intimating Yukio liked him anyway and he made his mommy smile when his daddy was gone. He looked up at the demon with an innocent look.

"Hehe.. okay Yukio. Would you like to meet your baby brother?" He asked quietly laughing when Yukio nodded so fast he nearly gave himself whip lash. So it was a boy! He had a baby brother!

"Okay, come on tyke. Just be quiet, your mommy is very tired. She will need her rest." He told him, Yukio nodded. Satan brought him over to the bed and set the boy on it.

"Hi mommy, is that my baby brother?" He asked trying to look into the wrapped up blanket.

"Yes baby. His... name is... Rin. Yukio... do you want to hold him?" his mommy said quietly with a smile, she was still breathing heavy.

"Yes mommy." He told her. Satan help the two, he fixed Yukio against the pillows and gently took the baby out of Yuri's arms. He gently placed the small baby in Yukio's arms and told him how to support him. Once Yukio was settled Satan stood close anyway in case anything happened.

"Why is he on fire?" Yukio asked looking up, wondering why the fire didn't even hurt him.

"He's half demon sweetie. He is like his daddy and me." Yuri explained as simply as she could.

"Oh." He said, it was so cool to him. He had a baby brother and he had superpowers!

"I'm a big brother! We can play and I can teach him stuff. And, and it will be so much fun!" Yukio said happily but careful not to jolt the baby. He was just so tiny.

"Wait until he is a bit older baby, then you can definitely do that." Yuri said smiling. She was happy to have her now two boys sitting like this. She knew Yukio would be a good older brother.

The baby stirred in Yukio's arm and opened his eyes. They were a shocking blue, just as Satan's are. They even had the same blood red iris. The baby looked at him for a minute before breaking out in tears and crying loudly. He shrieks were so loud! They had startled poor Yukio, Yuri laughed a bit and took the baby back into her tired arms.

"Let's let your mommy sleep bud. She and the baby need rest. We can go see the others. I'm sure they want to hear about their new baby brother." Satan said taking the child into his arms.

"Okay. Night mommy." Yukio said kissing her cheek when he leaned down. "Night Rin." Yukio said smiling down at his baby brother. Yuri said good night as her son was taken out of the room.

'I promise to protect you Rin.' Yukio thought to himself. 'Forever.'


	2. The Beginning Part 2

**_NEW FANCY UPDATED VERSION_**

 **DISCLAIMER: I sadly don't own Blue Exorcist. I shall now go cry about that. T^T.**

 **R &R!**

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 _'I promise to protect you Rin.'... 'Forever'_

That was five years ago, Yukio thought back to remembering that day. It was the day he became an older brother. It had been only to years after Rin was born that his mother was killed. It had not even been by demons, but by humans trying to rob their little home. She died protecting Yukio and Rin. It took forever to get his baby brother to stop crying. Satan had arrived and killed the men but was to late too save Yuri. He had held Yukio and Rin so close that day.

Yukio, unable to take care of his little brother Rin left with Satan for Gehenna. There was a problem though, once Rin left the Vatican thought it would be too dangerous for him to visit his brother. So Yukio hasn't seen his little brother since. Even since they found out they have tried to work something out so Rin could come without being hunted down by the exorcists.

Yukio had since then trained hard and became an exorcist under the guidance of Fujimoto Shiro. He wouldn't be weak as he had been when his mother died. He would be able to protect himself and other. He had advance so much that now he was a teacher and was helping train the next generation of exorcists. Right now though he should not be focused on the past but the future that is to come.

Now he and his students were at a camping trip. They were doing a series of tests to help them pass the upcoming exorcist exam.

"...Okumura!" Yukio jumped at the sound of his name being shouted right next to him. On instinct reached for his gun.

"Oi! No need for violence." Yukio realized it was Ryuji Suguro, otherwise known as Bon who was calling him. His top student.

"Oh, yes. What is it?" He asked putting on a smile.

"Teach,who were spaced out we had been calling out for you. There as a bright light that flashed just beyond those trees." He asked looking worried.

"Sorry I was think... wait? What!? Stay here all of you. I will go check it ou.." He never got to finish his sentence before he was interrupted.

"That will not be necessary Okumura." Said a voice coming out from beyond the tree line. Walked out of the bushes was no other that Amaimon, one of the eight demon kings.

"Amaimon? Is that really you?" Yukio said stepping back in shock lowering his gun. The other students looked either scared or shocked when the Demon King should up. Some (Bon) stared at their teacher in confusion he talked as if he personally knew the demon king.

"Of course its me.." Amaimon said with a neutral look on his face before he opened a sucker.

"What are you doing here?" Yukio asked as he placed his gun back in his holster, making the students question him.

"What I can't visit dear little Yuki?" Yukio gave a bitch face, which made the students question their teacher even further. Was this a trap for them this whole time?

"Fine, I came to give you good news. We've been approved." Yukio stepped back and his eyes shone. It looked as if...as if they were tears. He wiped his eyes with the back of his hand before anyone could get a closer look.

"Wh..Where is he?" Yukio asked making his voice sturdier.

"He's in the clearing just up ahead. He's waiting for you. The whole way here it was just 'where's Yuki? where he?' now you can deal with him." With that Yukio took off running, right past an 'evil and powerful' demon king nearly bumping into him.

"Wha.." The students all said in unison. They then realized they were left alone with a demon king. They backed up in fear of what might happen to them.

"Hmmm. Don't worry I won't kill you...yet. Though if you want to learn more about your teachers past I suggest you come. But don't disturb Yukio if you do, you will regret it. If that is too much to handle don't come." Amaimon said walking away.

"What do we do?" Shima asked to everyone.

"What do you think, we go!" Bon said running off into the same direction followed by everyone else. He was going to get to the bottom of this.

As they got to the clearing they saw Yukio still standing by the trees looking to be in shock. Confused the cram students looked at what he was staring at. They were surprised at what they saw.

In the center there was a little boy, who looked to be around five years old maybe four. But that is not what they were looking at, they were looking at his tail and pointed ears. Even though as demonic as he looked the child was sitting on the floor playing with the grass as any human child would. His back had been turned from Yukio so he had yet to see their teacher.

"...Rin..." Yukio said under his breathe. The little boy looked up at the sound, when he turned around immediately his eyes widened. He he stood up and began running at their teacher. They had all pulled out their weapons getting ready to kill the demon. Even though he may look like a child, he was a demon. Yukio heard the guns clicked and turned around his eyes widened. By him Amaimon's eyes widened and he was growling standing in a protective stance guarding the child.

"Stop!" Yukio yelled at them. "Don't you dare shoot!" They backed away from him in fear. They looked past him to see the demon child shaking in fear from their weapons.

Yukio turned back around to look at the child. "It's okay Rin they won't hurt you. Come here..." He said kneeling down holding his arms out. Seeing as the students where not going to shoot Rin ran to Yukio. What he yelled next nearly made the students drop their weapons.

"Nii-san!"He shouted as Yukio caught him.

"Come here Rin." Yukio said bringing him closer in his arms. He held the child as tight as he could in his arms and gently cradled his head.

"I miss' you Nii-san." The little boy said crying into Yukio's shoulder.

"What the hell is going on!?" Bon yelled loudly startling the two. He was becoming angry they were left in the dark like this.

Amaimon turned to them and growled threateningly.

"Be quiet. If you scare him you will pay, with your lives." They had never seen a Demon king looking so protective. The Ex-Wires wondered just who this little kid is.

_LITTLE BROTHER_

The group all went back to the campsite to discuss what happened. Amaimon held Rin in his arms. Yukio walked around the site and took down the barrier allowing Rin and Amaimon in. He knew no other demons would come with one of the kings here and the heir to Satan himself. When he was done Amaimon handed Rin back to him.

"Can you please explain what the hell is going on here?" Bon asked a bit more calm than before. (Mainly in fear of startling Rin and angering Amaimon).

"Well..um...you see..." Yukio started of not knowing what to say for once, the students had been surprised at this but not enough to let him off the hook.

"Well?" Shima asked to try and make him continue.

"Their brothers. Half-brothers actually." Amaimon said not wanting to wait for Yukio to build up the courage to speak.

"Wait...brothers?" Shiemi asked.

"Yes. My mother was also Rin's mother. My father had died a few years prior. When she fell in love with Rin's father they had Rin. I was eight at the time." Yukio said playing with Rin's hair gently, while the child was distracted with playing with the buttons on his coat.

"Wait then why is Amaimon here? He surly wouldn't be interested in a low class half-demon." Izumo asked.

"Generally no, I wouldn't care. Had he been the offspring of a lower class demon. But seeing as Rin is also my half-brother I care. His father is my father, and we have different mothers." Amaimon explained to them.

"Wait..."

"If Amaimon is his half-brother..."

"And they share fathers"

"That would have to mean..."

"RIN'S THE SON OF SATAN!" Konekomaru shouted loudly. He jumped away afraid of Rin attacking them.

This outburst though startled Rin and caused the five year old to burst out into tears.

"What did I say!?" Amaimon asked growling walking closer to Konekomaru who was now hiding behind Bon.

"Amaimon." Yukio said.

"What!" He shouted turning around to face Yukio only to see Rin still crying reaching out to him.

"*sniff* Nii-san" He said reaching out more. Amaimon gave Konekomaru one last glare before walking over to his brother lifting him into his arms.

"It's okay Rin. I will simply kill them if they hurt you." Rin either didn't understand or didn't care what Amaimon said. He simple buried his tear stained face in his older brother's chest.

"He's not dangerous. I mean look at him like he's what four!?" Bon said telling his friend.

"No! I'm five!" Rin yelled offended holding up five fingers. Amaimon took this moment to wipe Rin's face.

"Rin wouldn't hurt you Konekomaru. He is still half human and simply a child." Yukio said reassuring his student.

"That is correct young one." A deep voice sounded behind all of them. They turned around to see a white wolf covered in blue flames.

Satan himself.

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 **I know I am horribly neglectful. But I should be able to update frequently now. Please R &R!**


	3. The Beginning Part 3

**Disclaimer: I sadly do not anything the Blue Exorcist franchise. T^T**

 **Enjoy the fic please R &R**

 **PLEASE READ NOTICE AT CHAPTERS END!**

 **~Enjoy~**

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 _"Rin wouldn't hurt you Konekomaru. He is still half human and simply a child." Yukio said reassuring his student._

 _"That is correct young one." A deep voice sounded behind all of them. They turned around to see a white wolf covered in blue flames._

 _Satan himself._

"Daddy!" The little blue haired demon yelled out, he was squirming in his brother's arms until he was placed on the ground. Once his feet touched the tough surface Rin ran towards the white wolf. The ex-wires expected the demon child to be burned from the blue flames, or at least feel discomfort. This was not the case though once he reached the flaming wolf and wrapped his little arms best he could around its neck the child seemed perfectly content with the flames surrounding him.

"Daddy! I made it to Assiah! Did you see?!" He ranted off to the white wolf. Had the circumstances been different the students could almost see the duo as a normal child and father. Where the child tries to tell his father all about his day, his perfectly normal day. This, however, was not the case. Before them stood Satan and his son. Their _teacher's_ little brother.

"I did Rin. Now, why don't you go look around with Amaimon while I talk to Yukio?" He said nodding towards Amaimon who walked over to the two.

"Come on Rin. We can go see where Behemoth went." He said lifting his little brother into his arms and placing him on his back.

"Okay, Ami," Rin said as he wrapped his little arms around Amaimon's neck. Once the demon king knew his little brother was secure and settled he walked off in their search for his familiar. Once they were out sight Satan walked up to his to his step-son.

"Yukio as you know we have finally gotten the approval for Rin to travel between the worlds." At this Yukio gave a slight nod. "In order to maintain this agreement I have agreed that all plans of mine to take over Assiah shall be diminished. They have also agreed not to contact Rin or any others to do with him. If they harm him in any way I have permission to do whatever is necessary to protect my son. As if _I_ need _their_ permission." Satan informed him. The wolf had adopted a smug look to him. Yukio couldn't help but chuckle.

"I understand. I will watch him carefully. How long will he be standing in Assiah?" Yukio asked wanting to know how long he had with his little brother until he had to return.

"I have decided he will do intervals. For every month he is here he will spend the next two months in Gehenna for his lessons. So for this month, he will stay but then he shall leave for two months to study. While he is up here he could spend time with you and learn how to understand the world his mother came from. Do not worry about his studies, though, his tutors will handle everything." Satan explained remembering Yukio was always worrying about education.

"That is good. I will take him with me then. If I ever need help I am sure Mephisto will be willing to help." Yukio said smirking.

"Oh yes, as long as Rin doesn't touch his _precious collectables._ " This left the cram students confused as if there was a hidden joke only the two knew about.

"I must be returning now Yukio. Amaimon." Satan simple said and before he even finished he appeared with Rin climbing on his face.

"Help." He stated trying to get the little devil ( **hehehe** ) off him. Yukio chuckled and pulled his little brother off of his step-brothers face.

"Amaimon, please help watch over Rin when Yukio needs it. I will be leaving now." Rin heard this and started squirming in Yukio's arms. The older brother lets him down and the small demon ran over to the wolf.

"No daddy. Don' go." He said trying to wrap his little arms around the wolf's neck.

"I am sorry princeling. I am needed back in Gehenna. Be good for your brothers. I will return in a month's time so you may come home." He nuzzled Rin's hair with his nose before the wolf disappeared.

The little demon stood where the wolf was looking downcast, believing his father was forever leaving him.

"Come here, buddy," Yukio called out to his little brother kneeling down holding his arms out. The blue haired child ran to his brother only to be scooped up into his arms.

"Daddy left Yuki." He said burying his face in the elder's shoulder.

"I know but he will be back," Yukio said rubbing the little boys back.

"What if he doesn' come back like mummy did?" This made the other students and Yukio freeze. So that is what the child is thinking. His father is dying like his mother had.

"No bud. No. He will come back I promise." Yukio explained, he looked towards Amaimon for help.

"Oi Rin, later you wanna go annoy big brother with me?" The demon king asked. This seemed to do the trick as the little demon perked up.

"I wanna see Mephy! Can we sees Mephy Yuki?" He asked. Yukio knew he couldn't say no to those big blue eyes.

"Yeah, bud. I'm sure he would love to see you. Now, why don't we go to the campfire so you can meet everyone else, hm?" The child in his arms nodded happily.

Yukio walked over to his students and they followed him to the campfire. Yukio noticed the flames had gone out only leaving coals in the ring.

"Rin why don't you show me what your dad has taught you and light the fire for me?" Yukio asked. Rin nodded happily wanting to help his brother. With a slight nod from the little demon, the wood caught fire once again but was contained to the pit. The flames, though, they were not normal red flames. No, they burned bright blue before they faded to red. This made the cram students jump back, it had been unheard of for another to possess the flames of Satan. Until now, that is.

"Great job bud. So much better than when you lit my bedroom on fire." He said tickling Rin's stomach making the child giggle. Yukio sat on one of the logs with Rin, when he looked at his students they followed suit.

"I am sorry this has happened, everyone. I had not been expecting him to come back for another month or so, even if it was allowed." Yukio said bowing his head to them asking for forgiveness.

The students were not used to their teacher acting like this. Sheimi was the first to break the silence.

"It's okay Yuki. Now you have your little brother back, that's all that matters." She said smiling.

Everyone nodded the only nervous one seemed to be Konekomaru. Whether it was from Rin or Amaimon was unknown.

"Yukio I am going to go annoy our older brother. I will be back later." Before Yukio could even say anything Amaimon was gone.

"Okay, so why don't I introduce you. You all obviously know his name is Rin by now. Rin why don't you say hi to the others." Yukio said setting his brother Rin down.

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 **I. am. horrible... I wrote this a bit ago and never realised I didn'**


	4. First Night Home

Yukio lay in bed staring at the tent's roof. Rin had finally come back, his little brother was finally back in Assiah. He turned his head to look down at Rin. He was curled in a ball snugly against Yukio's side. There was going to be a lot to get used to, having to watch over his brother, but it was worth it. He knew he also had his step brothers help if needed. He would not have to do this alone.

Yukio gave a little chuckle when Rin started sneezed in his sleep. He pushed a few strands of his brother's hair away from his nose so he would stop sneezing. Even though it was cute he gave his little brother mercy and fixed his hair.

With Rin back, he would be able to show his little brother more of what their mother had been like. He would be able to tell him more about what she was like. He would be able to... Rin sneezed again. He would be able to give his brother an overdue haircut. Maybe he would be able to get Shiemi to help him in the morning.

There was a quiet rustle. "...Yukio?" sounded lowly in the tent. Yukio looked down to see Rin looking up at him rubbing his eyes.

"Hey, bud...what's wrong? You should be sleeping." Yukio said sighing as he once again had to brush hair out of his brother's eyes. He would defiantly be getting a haircut tomorrow.

"I miss' you big brother. I don' wan' you to go again." Yukio thought for a second before realizing. 'Why would Rin think..oh.'

"Rin..did you have a nightmare?" His brother looked down for a minute before nodding. "Oh Rin, I won't ever leave you."

Yukio wrapped his arms around Rin and hummed a lullaby to him. Yukio knew he can't sing but he can at least somewhat hold a tune whilst humming.

Within minutes Rin was asleep and Yukio fell asleep not long after knowing that once he woke up Rin would still be here.

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I know, I know this is short. But before you freak out it's short on purpose. I am taking one shot requests and maybe some small arcs for this story now. We are now past the prologue and I need requests. I know its late and I am sorry. But to make up for it hopefully, you will send in some requests. So fire away my little muffins! :) ~~~~


	5. What is he like?

**New chapter! I hope you all enjoy. Comment below with chapter requests. The more ideas I have the faster chapters can come.**

 **I hope you all like this one. Please do not comment flames.**

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Yukio ran a hand threw his hair with a sigh. It felt too early to possibly wake up. Taking a moment to think he shot out of his makeshift bed. He remember what happened last night. Rin was back! Looking around his heart skipped a beat. Where was Rin? He wasn't in the tent anywhere. Within seconds he was stumbling out of the tent ready to search for his brother.

"RI...Shiemi?" In front of Yukio sat Shiemi. It was not her that caught his eyes, no it was his little brother that sat in front of her. He was playing with a small flower crown.

"Oh, Y-Yukio! Good morning!" She greeted a bit too loudly causing Rin to flinch for a moment.

"Good morning, I was worried for a moment that Rin went missing during the night." He said as he walked over to the duo. He sat down next to Shiemi. The moment he was comfortable Rin crawled over to him and onto his lap.

"Oh, no. I'm sorry. It's just that I got up and I guess it woke up Rin. So he came out here and we have been here since. I even taught him how to make flower crowns." The moment she said this Rin reached up to his brother and placed a crown on his head.

Yukio smiled gently down at his brother, "thank you, Rin. Please, though, next time you hear something wake me first. I can bear having something happen to you." He warned gently.

Rin nodded slowly looking down. "Mhm, sorry big brother. I won' do it again." Looking up he gave Yukio puppy dog eyes.

He shook his head with a small chuckle, "I'm not mad. I was just worried." With that he pulled Rin closer to him in a hug. It lasted a few seconds before he heard the click of a phone camera and a giggle. Looking over he saw Shiemi taking pictures with her phone. For a moment she was so focused she didn't notice Yukio look at her. When she did she gasped before turning her head away blushing. Yukio chuckled once more, though she may be quiet Shiemi was quiet the fangirl when she wanted to be.

After that the trio sat together in blissful silence waiting for the others to wake. The only noise heard was Rin's gentle movement as he continued to weave the crowns.

It did not take too long before the others began to emerge from their tents. Bon was first and the rest followed soon after. Most of them sat around Rin with no problem. The only one that seemed to have and issue was Konekomaru. He sat on the opposite side of the fire pit and settled with simply glaring at Rin.

The silence did not last too long before Shima broke it with a question. "Soooo Rin. What's your dad like?" He didn't have a second to react before Bon punched his should ready to yell at him.

Before he had a chance to lecture about asking children about what their parent who just left for a month is like Rin started talking. "Daddy is funny! An' nice!" He stated with excitement.

All the exwires raised an eyebrow at this. 'Satan' and 'nice' didn't belong in the same thought let alone the same sentence.

"Really? How is _he_ nice?" Konekomaru asked with a bit too much venom. Rin didn't seem to notice this but Yukio did and he knew he would have to keep an eye on him.

"Well he lets me stay up late on weekends and he got me a puppy and he tells me stories and…" Rin was rambling on when Yukio covered his mouth.

"Remember Rin, breath in between words." He explained with a sigh. Some of the others laughed at this. Even though Rin was the son of Satan himself he really was just a little kid. If only Konekomaru could see this.

"What kind of storied does he tell you?" Shiemi asked gently leaning forward.

"Shorties 'bout mummy, Yukio, my other brothers, and other demon and…" Yukio sighed, Rin was a lost cause. It looks like he would never stop to take a breath.

Izumo perked up at this, "stories about Yukio, hmmm?" She looked over with an evil grin ready to find out some stuff about her teacher. At least she would have had Amaimon not appeared sitting next to them.

"Maimon!" Rin jumped off of Yukio's lap into his other brothers arms.

"Hey bud, I will play with you in a second. I have to tell Yukio and his students something." Looking over to them he said, "you all better start packing. Mephisto says you are needed back at the school. Something about something coming up or something like that." He told them no more as he was no distracted by Rin and his new flower crown making. He even placed one on Amaimon's head.

"Well, I guess that it then. The trip is over and we must start heading back. Get everything packed. We are heading back as soon as possible." Yukio commanded his students. They all set to packing. They were going back, now with two more people added to their group.


End file.
